Photographic developer



Patented Feb.15,1938 1 2,103,243-

UNITED STATES PATENT OFFICE 2,108,243 PHOTOGRAPHIC DEVELOPER Bruno Wendt, Dessau, Germany, assignor to Asia Ansco Corporation, Binghamton, N. Y., a. corporation or New York No Drawing. Application July 16, 1936, Serial No. 90,919. In Germany July 23, 1935 5 Claims. (CI. 95-88) My present invention relatesjo a photographic naphthalene-Z-carboxylic acid for the production developer and more particularly to a developer of a blue color.

for development in colors. The following examples illustrate the invention:

One of its objects is to provide an improved Emmple 1 5 developer. Another object is to provide an improved developer for development in colors. Fur- A developer consisting of: ther objects will be seen from the detailed. specification following hereaften 10.9 grams of unsymmetrical N.N-d1-(hydroxy- Para-phenylenediamine is used as a fine-grain 60 gg gg 'gi zgggm ggfgg gfig developer and derivatives of para-phenylenediamine have been proposed as developers. The lat- 1000 of water ter compounds, however, have not beeen introyields a 'y-value of 0.6 after minutes in a given duced into photographic practice because their emulsion. On the other hand, a developer conspeed in developing is relatively low. sisting of: 5 This invention relates to a process of photographic development in which N-hydroxyalkylg :22: g; gggi ggfi iffig figi ated para-phenylenediamines are used as developers. Examples of suitable compounds are un- 1000 of water symmetrical dihydroxydiethylpara-phenylenediand containing the same number of molecules of amine, methyl-hydroxyethylethyl-hydroxythe developing substance, yields in the same given ethyl-, butyl hydroxyethyl para phenylenediemulsion a 'y-value of 0.6 only after 75 minutes.

amine, as well as the corresponding toluidines. Also fi-y-dlhydroxy propyl para phenylenedi- Example 2 amines, such as the diamine itself and its alkyl- A developer consisting of:

25 derivatives. These compounds are obtainable by known methods from the corresponding aniline derivatives, the latter being converted into the nitroso-derivative and the nitroso-group be- 10 grams of i ing then reduced; or by coupling the hydroxygrams of caustlc soda alkyl-aniline derivative with an azo-component, 1000 of water for instance diazotized sulianilic acid, to make an yields green picture, whereas t known azo-dyestufi which is then reduced in the usual velopers having dibromooresol as a constituent manneryield only a blue-green color.

The unsymmetrical dihydroxy-diethyl-para- 10 grams of 2-amino-5-(N-hydroxyethyl-N- butyl) -amino-toluene-dihydrochloride phenylenediamine may be made from dihydroxy- Example 3 diethyl-aniline by converting the latter into its 9,0 grams of N ethyl N hydroxyethy] p nitroso-derivative and reducing the nitrosophenylene-djamine roup. Develope s ade wit t s mp 60.0 grams of anhydrous sodium sulfite velop about three times more quickly than that 05 gllam of potassium b d 40 made from non-substituted para-phenylenedi- 1000 cm f water amine and also yield very fine-grain negatives.

The developers have particularly good solubility, which is to be attributed to the hydroxyalkyl- First solution; group. Furthermore, the developers are particularly useful for development in color, since they gram N'Ndi'mydmxyethm) have the advantage over the normal alkyl-derivaene'dmmme tives that they yield purer and brighter colors. '100 of water Example 4 For the purpose of development in color there second solution; may be added to the developer besides the devel- J oping substance, substances which have a tendgram of phenyl-methyl-pyrazolone ency to produce dyestuffs during the development grams of anhydrous Sodium b nate by oxidation of the developer, for instance, a de- 100 of Waterrivative of acylacetic acid ester for the produc- Example 5 tion of a yellow color, pyrazolones for the production of a red color, and a derivative of l-hydroxy- First solution:

1.0 gram oi N.N-di-(hydroxyethyi) -p-pheny1- enediamine 100 cc. of water.

Second solution:

0.9 gram of o-phenyl-phenol 0.4 gram of caustic soda. 100 cc. of water.

In Examples 4 and 5 the two, solutions are mixed 10 before use.

What I claim is: 1. A photographic developer comprising an N- hydroxyalkylated'p-phenylenediamine.

2. A photographic developer comprising an N- hydroxyalkylated p-phenylenediamine and a compound capable of forming a dye with the oxidation products or the developer.

3. A photographic developer comprising unsymmetrical N.N di-(hydroxyethyl) -p-phenylenediamine.

4. A photographic developer comprising N- ethyl-N-hydroxyethyl-p-phenylenediamine, anhydrous sodium sulfite, potassium bromide and water. 

